condition mean min max ZT0-3 3.1804864999999998 2.1415629999999997 4.21941 ZT4-7 1.2466035 1.2466035 1.2466035 ZT8-11 0.7855179999999999 0.7855179999999999 0.7855179999999999 ZT12-15 0 0 0 ZT16-19 2.4558150000000003 2.4558150000000003 2.4558150000000003 ZT20-23 2.9337850000000003 2.9337850000000003 2.9337850000000003